Percentage of severely obese adults skyrockets

Two-thirds of American adults are either overweight or obese, and about 17 percent of children and teens are obese.

Associated Press file photo

Two-thirds of American adults are either overweight or obese, and about 17 percent of children and teens are obese.

The percentage of American adults who are 100 or more pounds over a healthy weight has skyrocketed since 2000, a study released Monday shows.

In 2010, about 6.6 percent of adults in this country were severely obese – about 15.5 million people – up from 3.9 percent in 2000, says the study from the RAND Corp., a non-profit research group.

“There is no question that severe obesity is going up very fast,” says lead author Roland Sturm, a senior economist at RAND. “Severe obesity has severe effects on quality of life, chronic conditions and health care costs.”

About two-thirds of people in the U.S. are either overweight or obese. People are considered obese if they have a body mass index (BMI) of 30 or higher, roughly 30 or more pounds over a healthy weight. People are severely (or extremely) obese if they have a BMI (a height-weight ratio) of 40 or higher. That’s roughly 100 or more pounds overweight.

“Moderate obesity (a BMI of 30 or more) has adverse health effects, but severe obesity is in a different league,” Sturm says. Severely obese people have far more complex health issues and create different challenges for the health-care system, he says. “Moderate obesity increases health care costs by 20 percent to 30 percent compared to those at a healthy weight, where severe obesity more than doubles health care costs.”

Sturm and colleagues write in the paper: “Physician offices and hospitals require additional resources for severely obese patients, who exceed limits on standard measuring and lifting equipment and may not fit standard imaging equipment, operating tables or wheelchairs.”

The new study is based on results of a telephone survey of about 3 million people over a decade from the Centers for Disease Control and Prevention. Because people tend to under-report their weight (more so for women) and over-report their height (more so for men), the researchers adjusted the findings for that potential bias.

The research, published online by the International Journal of Obesity found:

Severe obesity is about 50 percent higher among women than men.

It is about twice as high among blacks as Hispanics and whites.

The percentage of severely obese who are younger than 40 is similar to those who are older than 40.

“The younger group should normally be less overweight or obese,” Sturm says. “Yet for severe obesity, the young age group is already similar.”

Sturm speculates that one reason for the overall increase in severe obesity may be that “there is some genetic vulnerability among people, and in this environment where there’s an overabundance of food everywhere, people have become severely obese instead of just overweight.”